Spray device



May 29, 1951 s. A. w. JEURLING 2,554g829 SPRAY DEVICE Filed Nov. 24, 1948 Patented May 29, 1 951 SPRAY DEVICE Sten Anders Wilhelm J curling, Stockholm, Sweden, assigner to Super-Spray Paint Corporation, Kings County, N. Y.,l a corporation of New York Application November 24, 1948, Serial No. v61,877

In Sweden December 1, 1947 l This invention relates to spray devices for lquied material, such as paint, and more particularly to such devices having a nozzle unit for the material to be sprayed and gaseous spray pressure medium for spraying said material and laterally of the axis of said nozzle a gas burner having orices for ejecting gas to form flames substantially in the same direction as that of the sprayed material so as more or less completely to surround the jet of sprayed material. Due to the considerable speed of the sprayed jet of the liquied material there is a tendency of establishing a vacuum round the jet and in consequence thereof the flames will decline towards said jet and may converge too much and even burn the jet. a

The primary object of the invention is therefore to eliminate the vacuum between the jet of liquied material and the ames and a second object is to provide means for performing such eliminating without unduly cooling the liquied material or the thing to be sprayed. A-

further object is to provide means for controlling the degree of elimination of the vacuum, at least partially for the purpose of influencing the direction of the flames. It is also an object of the invention so to design the spray device as to prevent the combustible burner gases from being intermingled with the spray pressure medium or any other gases in channels of the device containing oxygen. A still further object is to provide a sprayer having a readily removable or exchangeable burner so as to enable one and the same spray gun to be used for different purposes.

To obtain these objects and other advantages that will be evident from the following description at least one conduit is provided to connect the space between the nozzle unit for the liquied material and the orifices of the burner with the surrounding atmosphere or with a source of pressure gas, at least in the latter case means being provided for heating said pressure gas.

The invention will now be described more in detail with reference to the accompanying drawing, but it is to be understood that the invention shall not be limited to the embodiments thus described or shown.

In the drawing-- The figure is a schematic side view partially in section, of a nozzle head in accordance with my present invention.

Being particularly applicable to thehot spraying of heated paint, the invention will now be described with reference to that kind of liqui- `7 claims. (o1. 91-45) y fled material, although it may be used with advantage also for other materials.

In a metallic block or body I a central bore or recess 4 is provided to give room for the nozzle unit which will be described presently. At some distance laterally of said bore or recess is another recess 2 and between this recess and the bore 4 there is a further recess 3. A tube Il f for heated paint is attached to the rear side of the bore 4 and a flanged nozzle body 5 is partly inserted into the inner end of the tube Il, the flange 1 of said nozzle body being seated on corresponding shoulder in the bore 4. The body 5 has a central paint chamber 6 having a front orifice I5 in an extended portion of body 5. The various recesses 2, 3 and 4 are closed at the front side by a cover 9 secured to the body I by means of threads II, so as to form from said recesses a burner gas chamber 2, a protection gas chamber 3 Yand a spray gas chamber 8. This cover 9 is provided with a series of orifices I2 along the burner chamber 2 and orifices I3 along the protection gas chamber 3. Around the extended portion I5 of the nozzle' body 5 there is a hole I4 in the cover 9 of such a width that an annular orice I6 will be formed about said extended portion so as to form an outlet for the chamber `Il.

The various gas chambers 2, 3 and 8 are connected to corresponding supply conduits I8, I9 and 2D, respectively, for supplying burner gas or air-gas mixture, protection gas and spray pressure gas, respectively. A heating member is provided at least in the protection gas conduit I9 as indicated by the electrical resistance I0, but preferably also in the pressure medium conduit 2i! as indicated by I0. It is to be understood that the invention is by no meansnrestricted to electrical heating means but may as Well make use of any practical heating means, such as a steam jacket or a gas burner. The heating member may preferably be arranged in or about the source of protecting gas or spray gas, respectively.

All the conduits II--2Il leading to the nozzle head but in particular the protection gas conduit I9 may be provided with a control valve 2|, 2|.

The nozzle unit 5, III-I6 may have any suitable form for providing a paint jet of any desired shape. Thus circular orices I5 and I6 will form a circular jet and adequate means, Well known to those skilled in the art, will render a more or less flattened jet. The chambers 2 and 3 are preferably shaped so as to correspond to the shape of the paint jet. The distances between, on the one hand, the orifices I2 and I3 and, on the other hand, the paint jet will in such case be substantially equal. In case of a circular jet the chambers 2 and 3 are preferably Aannular and the corresponding re'- cesses are then easily turned in the nozzle block I. For ilattened jets the chambers 2 and 3 may be more or less rectilinear.

In operating this device compressed air is admitted through the conduit 20 to chamber 8 and a jet of air will be ejected through the orifice I6. Burner gas, which may be an appropriate lmix'- ture of combustible gas and air, .is simultaneously admitted to chamber 2 through conduit I8 and the gas is ignited at the orifices I2. Protection gas is supplied through conduit I9 to vchamber f3 and the valve 2I is regulated until the desired direction of the flames from the orifices I2`will be obtained. The heating member I and, if desired, the heating member I0 are regulated according to the prevailing conditions. .By suitable setting of the valves 2l and. 2I and appropriate supply of burner gas through conduit IB just so great a portion as desired 'of the surface fof `the object to be `painted will be :covered by the -flames from the burner 2. When the .correct .adjustment of the supply of the various gases has been attained, the heated paint Will be admitted through 'conduit I'I to the paint chamber 6 and the paint will then be -ejected by the sucking iniiuence of the pressure air forced out through the orice IB.

The means for supplying paint and burner :gas and the various containers for paint, 4burner fgas and pressure gas being commonly known to lthose skilled in the art, such means will not be described here.

Having now particularly described Yand ascertained the nature of my said invention and in what manner the sam'e is to be performed I declare that what I claim is:

1. A spray vdevice having a nozzle unit for liquied material to be sprayed and `for gaseous spray pressure 'medium for spraying said material, laterally of the axis of said nozzle a gas' burner having orices for ejecting flames substantially in the direction of the axis of said nozzle, a source of protection gas, at least one 5 conduit connecting the space between said nozzle @d 'said orifices with said source, 'and means for heating said .protection gas.

2. A spray device as claimed in claim 1, characterized in means in said conduit for controlling the flow of gas therein.

3. A spray device as claimed in claim 1, characterized in means for heating said spray pressure medium.

'4. ,-A spray device, comprising a block, in said block at the Icentre a spray material chamber and a spray medium chamber, laterally of said chambers a protection gas chamber and further laterally of the last named chamber a burner gas chamber, all said chambers having supply conduits and forwardly directed exit orifices, at least the supply conduit -of said protectiongas chamber being provided with gas heating means.

5. A spray device vas claimed in claim 4, comprising in at least the `supply conduit of said protection gas 'chamber a control valve.

'6. A spray device as claimed in claim 1, in which the orifices Yof said gas burner are situated substantialiy `at the same distance from the jet of rliquied materia-l ejected from the nozzle.

'7. A spray device as claimed in vclaim il, comprising a vnozzle head and yin said head a distributionchamber Ifor combustiblegas and a distribution chamber for pressure medium, a centinual impervious wall being :arranged between said 35 chambers.

STEN ANDERS WILHELM JEURLING.

REFERENCES oITED The following references are of record in the fue of this patent:

UNrrED STATES PATENTS Number :Name Date v2,410,532 'I-essier Nov. 5, 1946 5 2,438,471 Ball Mar. 23, 1948 

